ADAPTIVE TIME-STEP CONTROL FOR THE MODAL METHOD TO INTEGRATE THE MULTIGROUP NEUTRON DIFFUSION EQUATIONA. Carreño, A. Vidal-Ferràndiz, D. Ginestar and G. VerdúEPJ Web Conf., 247 (2021) 07010DOI: https://doi.org/10.1051/epjconf/202124707010